Diquat
Wallingford Water Department
Diquat is a herbicide used on potato crops and aquatic weeds.
9
Samples
0
Samples exceeding legal limit (MCL)
0
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2013 | N/A | 0 | 0 | N/A |
| 2014 | N/A | 0 | 0 | N/A |
| 2015 | N/A | 0 | 0 | N/A |
| 2016 | ND | 4 | 0 | ND |
| 2017 | N/A | 0 | 0 | N/A |
| 2018 | N/A | 0 | 0 | N/A |
| 2019 | ND | 5 | 0 | ND |
ppb = parts per billion
State and national drinking water standards and health guidelines
EWG Health Guideline 6 ppb
The EWG Health Guideline of 6 ppb for diquat was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against cataracts.
EPA Maximum Contaminant
Level (MCL) 20 ppb
The legal limit for diquat, established in 1992, was based on a toxicity study in laboratory animals conducted in the 1980s.
ppb = parts per billion
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2016-07-28 | 11609-01SOC5 | ND |
| 2016-07-28 | 11610-01SOC5 | ND |
| 2016-10-26 | 16308-01SOC5 | ND |
| 2016-10-26 | 16309-01SOC5 | ND |
| 2019-08-05 | CD73202-P5 | ND |
| 2019-08-12 | CD83465-P5 | ND |
| 2019-09-16 | CE10614-P5 | ND |
| 2019-10-10 | CE30938-P5 | ND |
| 2019-11-04 | CE53371-P5 | ND |